New Delhi, Sept. 24 -- Parts of Kolkata recorded 9.8 cm rain in an hour, almost reaching cloudburst intensity, on Tuesday early morning. A cloud burst is a very localised phenomenon when an area receives more than 10cm of rain in an hour. Nevertheless, the rain intensity was so high in Kolkata that it severely flooded several parts of the city, as it prepares for Durga puja festivities later this week. "Maximum highest hourly rainfall observed as 98 mm between 03:00 to 04: 00 hours IST of 23 September,2025. As it is less than 100 mm, it does not satisfy the cloudburst criteria," India Meteorological Department said on Tuesday. A low-pressure has formed on 22 morning and it slowly moved to coastal areas of Gangetic West Bengal and adjoining north Odisha and northwest Bay of Bengal in the morning of September 23. Under its influence strong moisture convergence persisted over Kolkata and the neighbourhood area. Kolkata Doppler weather Radar image as depicted below shown high moisture content persisted over Kolkata area with cloud height about 5 to 7 km, IMD added. Extremely heavy rainfall of amount 251.4mm occurred over Kolkata in 24 hours period recorded at 8.30am on Tuesday. A low pressure area is lying over coastal areas of Gangetic West Bengal and adjoining north Odisha and northwest Bay of Bengal and a fresh low-pressure area is likely to form over northwest and adjoining central Bay of Bengal around September 25. Under the influence of these systems, heavy to very heavy rainfall likely over Gangetic West Bengal on Tuesday, IMD said....